Extension for a golf club shaft and method of installing the same

ABSTRACT

An apparatus for extending a length of a golf club shaft is disclosed. The apparatus includes an expandable plug with an extension length that is fitted in the hollow interior of a shaft of the golf club in a grip area of the club. The plug has wedge portions which provide the mechanism for anchoring the plug to the golf club shaft. The plug may be provided as part of a kit including instructions related to the plug and a golf club. The kit may allow the plug to be retrofitted on an existing golf club to alter a length of the club. A method of extending the length of the golf club is also disclosed.

BACKGROUND OF THE DISCLOSURE

The disclosure relates to a plug with an extension length which may be fitted to a shaft of a golf club to extend a length of the golf club shaft. More particularly, the disclosure relates to a plug with an extension length that may be fitted in a hollow interior of the shaft in a grip area of the club and solely secure the plug to the shaft without the need for fasteners or other adhesives.

As disclosed herein, a user may alter a length of a shaft of a club with the plug and extension. For instance, a young golfer may increase the shaft length as he or she grows using the plug disclosed herein to obviate the need to buy a new club. Because the plug is fitted to the shaft at an end of the shaft in the grip area and covered with a grip, the golf club maintains its aesthetically pleasing look.

SUMMARY OF THE INVENTION

In one aspect of the invention a method is provided. The method comprises providing a golf club with a head and a shaft extending from the head to a grip area of the club where the grip area is adapted to receive a grip for the club and the shaft has a hollow interior adjacent the grip area. The method also comprises providing an expandable plug that comprises top and bottom wedge portions each with outer engagement surfaces and opposed angled faces adapted for abutting sliding contact. The bottom wedge portion has a threaded hole adapted to receive a threaded connector. The top wedge portion has an extension length extending axially from the outer engagement surface, an access surface opposite the angled face, a first bore extending from the access surface and partially through the top wedge portion thereby forming an internal seat therein spaced from the angled surface, and a second bore extending from the seat to the angled face. The top wedge portion second bore is larger than a diameter of a shaft of the connector and allows the top wedge portion to move laterally relative to the connector. The top wedge portion first bore is larger than a diameter of a head of the connector and allows the connector head to slide therein. The method further comprises inserting the outer engagement surfaces of the plug top and bottom wedge portions into the shaft hollow interior in the grip area, and inserting the connector through the top wedge portion first and second bores into the bottom wedge portion threaded hole such that the opposed angled faces of the top and bottom wedge portions abut and slide in a manner that permits the outer engagement surfaces of the top and bottom wedge portions to engage against the shaft and solely secure the plug to the shaft.

In another aspect of the invention a kit is provided. The kit comprises an expandable plug having top and bottom wedge portions each with outer engagement surfaces and opposed angled faces adapted for abutting sliding contact. The bottom wedge portion has a threaded hole adapted to receive a threaded connector. The top wedge portion includes an extension length extending axially from the outer engagement surface, an access surface opposite the angled face, a first bore extending from the access surface and partially through the top wedge portion thereby forming an internal seat spaced from the angled surface, and a second bore extending from the seat to the angled face. The top wedge portion second bore is larger than a diameter of a shaft of the connector and allows the top wedge portion to move laterally relative to the connector. The top wedge portion first bore is larger than a diameter of a head of the connector and allows the connector head to slide therein. The kit also comprises a connector having a length sufficient to extend through the top wedge portion first and second bores into the bottom wedge portion threaded hole such that as the connector is threaded, the opposed angled faces of the top and bottom wedge portions abut and slide in a manner that permits the outer engagement surfaces of the top and bottom wedge portions to move in opposite directions. The kit also includes instructions relating to the plug and a golf club.

In another aspect of the invention, a golf club is provided. The golf club includes a head and a shaft extending from the head to a grip area of the club with the grip area being adapted to receive a grip for the club and the shaft having a hollow interior adjacent the grip area. The golf club further comprises a plug disposed in the shaft hollow interior in the grip area. The plug comprises top and bottom wedge portions each with outer engagement surfaces engaging a surface defining the shaft hollow interior and solely securing the plug to the shaft. The top wedge portion has an angled face abutting an angled face of the bottom wedge portion. The bottom wedge portion has a threaded hole for a connector of the plug. The top wedge portion includes an extension length extending axially from the outer engagement surface and an access surface axially opposite the angled face. The top wedge portion has a first bore extending from the access surface and partially through the top wedge portion thereby forming an internal seat spaced from the top wedge portion angled surface. The top wedge portion also has a second bore extending from the internal seat to the top wedge portion angled face. The top wedge portion second bore is larger than a diameter of a shaft of the connector, and the top wedge portion first bore is larger than a diameter of a head of the connector. The connector extends through the top wedge portion first and second bores into the bottom wedge portion threaded hole in a manner to maintain the opposed angled faces of the top and bottom wedge portions in abutting contact and the outer engagement surfaces of the top and bottom wedge portions in engagement with the shaft.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a perspective view of a golf club with conventional breaks on a shaft of the club to show the relative position of a head of the club and a grip area of the club, and an expandable plug and an extension length are shown in an exploded fashion in the grip area of the club within a cut-away view of the grip;

FIG. 2 shows a cross-sectional view of a grip of the golf club with a plug secured within a hollow interior of the grip;

FIG. 3 shows a side exploded cross-sectional view of an expandable plug with extension length and a connector of the plug;

FIG. 4 shows an end view of the connector inserted into an expandable plug; and

FIG. 5 shows a representative kit of the disclosure comprising a blister package with two grips of different lengths and two plugs of different lengths along with instructions relating to the plugs.

DESCRIPTION OF THE EMBODIMENTS

As shown in FIG. 1, the golf club 20 comprises a head 22 with the shaft 24 extending between the head 22 and a grip area 26 of the club. Although a wood is shown in the drawing figures, the principles of the disclosure may be practiced with any golf club, including an iron or putter. The grip area 26 of the club extends partially down the shaft 24 a short distance toward the head 22 and is adapted to receive a grip 28 of the club. The shaft 24 is generally a cylindrical tapered tube with a hollow interior. Depending upon the type and length of the shaft, i.e., a composite (graphite) or steel, the wall thickness of the shaft may vary. To extend the length of the shaft, an expandable plug 30 is fitted in a hollow interior 32 of the shaft as shown in FIG. 1.

As shown in FIGS. 2 and 3, the plug comprises top and bottom wedge portions 34, 36 each with outer engagement surfaces 38, 40 and each with opposed angled faces 42,44. The angled faces 42,44 are adapted to abut and slide relative to one another as the plug 30 is installed in the shaft hollow interior. As will be explained below, when the plug is installed in the shaft hollow interior, the angled faces of the top and bottom wedge portions come into contact with each other and slide relative to one another, causing the top and bottom wedge portions to move in opposite directions and bring the top and bottom outer engagement surfaces into contact with a surface in the shaft hollow interior, for instance, the interior wall of the shaft. Although the top and bottom wedge portions are shown with cylindrically shaped outer engagement portions, other shapes may also be used and are considered within the scope of the invention.

Referring to FIGS. 2 and 3, the plug bottom wedge portion 36 has a threaded hole 46 that is adapted to receive a threaded connector. The plug top wedge portion 34 has an extension length 48 extending axially from the outer engagement surface 38. The top wedge portion has an access surface 50 opposite the angled face 42 and a first bore 52 extending from the access surface and partially through the top wedge portion. The first bore 52 forms an internal seat 54 in the top wedge portion for engaging a head of the threaded connector, as will be explained in greater detail below. The top wedge portion 34 has a second bore 56 that extends from the seat 54 to the angled face 42. The second bore 56 is larger than a diameter of a shaft of the connector and adapted to allow the top wedge portion to move laterally relative to the connector, as will be explained below in greater detail. The top wedge portion first bore 52 is larger than a diameter of the head of the connector and is adapted to allow the head of the connector head to slide therein to facilitate installation of the plug and connector, as will be explained below. The second bore 56 may extend partially through the bottom wedge portion 36 before terminating at the threaded hole 46.

The top wedge portion extension length 48 may be sized along its longitudinal length in accordance with a user's preference for a length of a golf club shaft. As shown in FIG. 3, the extension length 48 may have longitudinal ribs 58 circumferentially spaced about the extension length. The ribs 58 facilitate anchoring the grip 28 to the shaft of the club and prevent rotation of the grip on the shaft.

Referring again to FIGS. 2 and 3, a threaded connector 60 is directed through the first bore 52 in the access surface, through the second bore 56, and into the threaded hole 46 of the bottom wedge portion 36. Continued insertion or threading of the connector 60 into the bottom wedge portion 36 with the bottom wedge portion restrained draws the bottom wedge portion angled face 44 into abutting and sliding contact with the top wedge portion angled face 42. With the top and bottom wedge portions 34,36 in close proximity, the angled faces 42,44 of the wedge portions tend to engage each other and prevent rotation when the connector 60 is threaded further into the bottom wedge portion. As the connector 60 is threaded sufficiently into the threaded hole 46 of the bottom wedge portion and the connector head is drawn tightly against the internal seat 54 of the top wedge portion, the bottom wedge portion and top wedge portion engage and slide along their respective angled faces in opposite directions. The sliding motion generates relative lateral movement between the top and bottom wedge portions. The amount of relative lateral movement is in part determined by a diameter of the second bore 56 and a diameter of a shaft of the connector 60. Extending the second bore into the bottom wedge piece tends to increase the amount of relative lateral movement of the wedge pieces.

In operation, the plug 30 is inserted into the shaft hollow interior 32 in the grip area 26 of the shaft as shown in FIG. 1. Preferably, the outer engagement surfaces 38,40 of the plug top and bottom wedge portions 34,36 are inserted completely into the shaft hollow interior 32 such that only the extension length 48 extends from an end of the shaft. If the plug is being used in a golf club having an existing grip, the grip is removed from the grip area to expose the shaft hollow interior. However, as disclosed herein, a plug may be inserted into a hollow interior shaft of a new golf club during manufacture of the club and before any grip is installed. Once the outer engagement surfaces 38,40 of the top and bottom wedge portions are inserted into the shaft hollow interior 32, the threaded connector 60 is tightened thereby drawing the wedge portions respective faces into abutting and sliding contact and forcing the bottom wedge portion to move in a direction opposite the top wedge portion. This movement increases the size (for instance, the overall effective diameter) of the plug thereby allowing the plug to securely engage the shaft without the need for glue or other adhesives. With a tight mechanical fit provided solely by the plug, the user may fully utilize the club.

The grip 28 may be then installed over the extension length 48 (and/or the plug) and partially over the shaft 24 in the grip area 26 to provide an aesthetically pleasing look for the golf club. The grip may be attached to the shaft in the grip area and over the extension length with a suitable adhesives.

As an alternative, the grip 28 may be provided with the plug as described above, as an integral unit. As shown in FIG. 2, the plug may be securely held in a hollow interior of the grip 28 in a substantially coaxially alignment with the grip prior to its installation on a golf club. The plug may be secured to the grip at the access surface of the top wedge portion with adhesive or may be secured to the extension length with adhesive. Accordingly, when the plug is inserted into the hollow interior of the shaft as described above, the grip is installed in the grip area of the club in essentially one step.

In order to allow air to escape from the shaft, the threaded connector 60 may be provided with a hollow interior 70 that communicates with the shaft hollow interior 32. The connector may be a socket head type screw which may be tightened with a conventional hex wrench.

The plug 30 may be provided as a part of a kit 80 comprising a plug and a connector, as described previously, along with instructions 82 relating to the plug, for instance, installation of the plug in the shaft. The instructions may comprise graphics or illustrations or text, or advertising material promoting the kit. Other variations of the kit include providing one or more grips, the grip being integral with the plug (for instance, as shown in FIG. 2), a tool(s) for installation of the plug in the shaft, grips with different lengths, plugs with varying extension lengths, grips corresponding to the plugs, and/or connectors with varying lengths corresponding to the plugs. For instance, a kit as shown in FIG. 5 may include plugs with extension lengths varying in one-half inch increments and a set of matching grips for use with each plug. A kit may allow a user to select a plug from amongst a plurality of plugs based upon a desired extension length. A kit may provide a convenient way for a user to customize a length of the golf club shaft. For instance, if the user desires to change the length of the club, the user may remove the grip from the grip area, unthread the connector from the plug bottom wedge portion, remove the plug, and install a new desired plug. The grip(s) provided in the kit may then be used with the newly installed plug.

As shown in the drawings, the top wedge portion extension length and the top wedge portion outer engagement surface are monolithically formed. However, the top wedge portion extension length and top wedge portion outer engagement surface may be separate pieces held together in the shaft of the hollow golf club by the connector.

While specific embodiments have been described in detail in the foregoing detailed description and illustrated in the accompanying drawings, those with ordinary skill in the art will appreciate that various modifications and alternatives to those details could be developed in light of the overall teachings of the disclosure. Accordingly, the particular arrangements disclosed are meant to be illustrative only and not limiting as to the scope of the invention, which is to be given the full breadth of the appended claims and any and all equivalents thereof. 

1-14. (canceled)
 15. The golf club of claim 19 further comprising a grip over the extension length in the grip area.
 16. The golf club of claim 19 wherein the plug is inserted into the shaft hollow interior such that only the top wedge portion extension length is exposed from the hollow shaft.
 17. The golf club of claim 19 wherein the shaft is formed from a composite material.
 18. The golf club of claim 19 wherein the top wedge portion extension length and top wedge portion outer engagement surface are monolithically formed.
 19. A golf club comprising: a head and a shaft extending from the head to a grip area of the club, the grip area being adapted to receive a grip for the club, the shaft having a hollow interior adjacent the grip area; and a plug disposed in the shaft hollow interior in the grip area, the plug comprising top and bottom wedge portions each with outer engagement surfaces engaging a surface defining the shaft hollow interior and solely securing the plug to the shaft, the top wedge portion having an angled face abutting an angled face of the bottom wedge portion, the bottom wedge portion having a threaded hole for a connector of the plug, the top wedge portion including an extension length extending axially from the outer engagement surface and an access surface axially opposite the angled face, the top wedge portion having a first bore extending from the access surface and partially through the top wedge portion thereby forming an internal seat spaced from the top wedge portion angled surface, the top wedge portion having a second bore extending from the internal seat to the top wedge portion angled face, the top wedge portion second bore being larger than a diameter of a shaft of the connector, the top wedge portion first bore being larger than a diameter of a head of the connector; the connector extending through the top wedge portion first and second bores into the bottom wedge portion threaded hole in a manner to maintain the opposed angled faces of the top and bottom wedge portions in abutting contact and the outer engagement surfaces of the top and bottom wedge portions in engagement with the shaft, the connector having a hollow interior in communication with the shaft hollow interior; wherein the connector has a hollow interior in communication with the shaft hollow interior.
 20. The golf club of claim 19 wherein the top wedge portion extension length has longitudinal ribs. 21-22. (canceled) 